mentioned in the previous paragraph,
limited to the information that <i>W</i> directly observes.
</p>

<p>
The <i>happens before</i> relation is defined as the transitive closure of the
union of the sequenced before and synchronized before relations.
</p>

<p>
<b>Requirement 3</b>:
For an ordinary (non-synchronizing) data read <i>r</i> on a memory location <i>x</i>,

name <code>E</code> in place of a method specification. This is called
<i>embedding</i> interface <code>E</code> in <code>T</code>.
The <a href="#Method_sets">method set</a> of <code>T</code> is the <i>union</i>
of the method sets of <code>T</code>’s explicitly declared methods and of
<code>T</code>’s embedded interfaces.
</p>

<pre>
type Reader interface {
	Read(p []byte) (n int, err error)

	<li>The type set of a term of the form <code>~T</code>
		is the set of all types whose underlying type is <code>T</code>.
	</li>

	<li>The type set of a <i>union</i> of terms
		<code>t<sub>1</sub>|t<sub>2</sub>|…|t<sub>n</sub></code>
		is the union of the type sets of the terms.
	</li>
</ul>

<p>
The quantification "the set of all non-interface types" refers not just to all (non-interface)